diff options
| -rw-r--r-- | cloudinit/registry.py | 23 | ||||
| -rw-r--r-- | cloudinit/reporting.py | 122 | ||||
| -rw-r--r-- | tests/unittests/test_registry.py | 28 | ||||
| -rw-r--r-- | tests/unittests/test_reporting.py | 192 |
4 files changed, 365 insertions, 0 deletions
diff --git a/cloudinit/registry.py b/cloudinit/registry.py new file mode 100644 index 00000000..46cf0585 --- /dev/null +++ b/cloudinit/registry.py @@ -0,0 +1,23 @@ +import copy + + +class DictRegistry(object): + """A simple registry for a mapping of objects.""" + + def __init__(self): + self._items = {} + + def register_item(self, key, item): + """Add item to the registry.""" + if key in self._items: + raise ValueError( + 'Item already registered with key {0}'.format(key)) + self._items[key] = item + + @property + def registered_items(self): + """All the items that have been registered. + + This cannot be used to modify the contents of the registry. + """ + return copy.copy(self._items) diff --git a/cloudinit/reporting.py b/cloudinit/reporting.py new file mode 100644 index 00000000..d2dd4fec --- /dev/null +++ b/cloudinit/reporting.py @@ -0,0 +1,122 @@ +# Copyright 2015 Canonical Ltd. +# This file is part of cloud-init. See LICENCE file for license information. +# +# vi: ts=4 expandtab +""" +cloud-init reporting framework + +The reporting framework is intended to allow all parts of cloud-init to +report events in a structured manner. +""" + +import abc +import logging + +from cloudinit.registry import DictRegistry + + +FINISH_EVENT_TYPE = 'finish' +START_EVENT_TYPE = 'start' + +DEFAULT_CONFIG = { + 'logging': {'type': 'log'}, +} + + +instantiated_handler_registry = DictRegistry() +available_handlers = DictRegistry() + + +class ReportingEvent(object): + """Encapsulation of event formatting.""" + + def __init__(self, event_type, name, description): + self.event_type = event_type + self.name = name + self.description = description + + def as_string(self): + """The event represented as a string.""" + return '{0}: {1}: {2}'.format( + self.event_type, self.name, self.description) + + +class FinishReportingEvent(ReportingEvent): + + def __init__(self, name, description, successful=None): + super(FinishReportingEvent, self).__init__( + FINISH_EVENT_TYPE, name, description) + self.successful = successful + + def as_string(self): + if self.successful is None: + return super(FinishReportingEvent, self).as_string() + success_string = 'success' if self.successful else 'fail' + return '{0}: {1}: {2}: {3}'.format( + self.event_type, self.name, success_string, self.description) + + +class ReportingHandler(object): + + @abc.abstractmethod + def publish_event(self, event): + raise NotImplementedError + + +class LogHandler(ReportingHandler): + """Publishes events to the cloud-init log at the ``INFO`` log level.""" + + def publish_event(self, event): + """Publish an event to the ``INFO`` log level.""" + logger = logging.getLogger( + '.'.join([__name__, event.event_type, event.name])) + logger.info(event.as_string()) + + +def add_configuration(config): + for handler_name, handler_config in config.items(): + handler_config = handler_config.copy() + cls = available_handlers.registered_items[handler_config.pop('type')] + instance = cls(**handler_config) + instantiated_handler_registry.register_item(handler_name, instance) + + +def report_event(event): + """Report an event to all registered event handlers. + + This should generally be called via one of the other functions in + the reporting module. + + :param event_type: + The type of the event; this should be a constant from the + reporting module. + """ + for _, handler in instantiated_handler_registry.registered_items.items(): + handler.publish_event(event) + + +def report_finish_event(event_name, event_description, successful=None): + """Report a "finish" event. + + See :py:func:`.report_event` for parameter details. + """ + event = FinishReportingEvent(event_name, event_description, successful) + return report_event(event) + + +def report_start_event(event_name, event_description): + """Report a "start" event. + + :param event_name: + The name of the event; this should be a topic which events would + share (e.g. it will be the same for start and finish events). + + :param event_description: + A human-readable description of the event that has occurred. + """ + event = ReportingEvent(START_EVENT_TYPE, event_name, event_description) + return report_event(event) + + +available_handlers.register_item('log', LogHandler) +add_configuration(DEFAULT_CONFIG) diff --git a/tests/unittests/test_registry.py b/tests/unittests/test_registry.py new file mode 100644 index 00000000..bcf01475 --- /dev/null +++ b/tests/unittests/test_registry.py @@ -0,0 +1,28 @@ +from cloudinit.registry import DictRegistry + +from .helpers import (mock, TestCase) + + +class TestDictRegistry(TestCase): + + def test_added_item_included_in_output(self): + registry = DictRegistry() + item_key, item_to_register = 'test_key', mock.Mock() + registry.register_item(item_key, item_to_register) + self.assertEqual({item_key: item_to_register}, + registry.registered_items) + + def test_registry_starts_out_empty(self): + self.assertEqual({}, DictRegistry().registered_items) + + def test_modifying_registered_items_isnt_exposed_to_other_callers(self): + registry = DictRegistry() + registry.registered_items['test_item'] = mock.Mock() + self.assertEqual({}, registry.registered_items) + + def test_keys_cannot_be_replaced(self): + registry = DictRegistry() + item_key = 'test_key' + registry.register_item(item_key, mock.Mock()) + self.assertRaises(ValueError, + registry.register_item, item_key, mock.Mock()) diff --git a/tests/unittests/test_reporting.py b/tests/unittests/test_reporting.py new file mode 100644 index 00000000..f4011a79 --- /dev/null +++ b/tests/unittests/test_reporting.py @@ -0,0 +1,192 @@ +# Copyright 2015 Canonical Ltd. +# This file is part of cloud-init. See LICENCE file for license information. +# +# vi: ts=4 expandtab + +from cloudinit import reporting + +from .helpers import (mock, TestCase) + + +def _fake_registry(): + return mock.Mock(registered_items={'a': mock.MagicMock(), + 'b': mock.MagicMock()}) + + +class TestReportStartEvent(TestCase): + + @mock.patch('cloudinit.reporting.instantiated_handler_registry', + new_callable=_fake_registry) + def test_report_start_event_passes_something_with_as_string_to_handlers( + self, instantiated_handler_registry): + event_name, event_description = 'my_test_event', 'my description' + reporting.report_start_event(event_name, event_description) + expected_string_representation = ': '.join( + ['start', event_name, event_description]) + for _, handler in ( + instantiated_handler_registry.registered_items.items()): + self.assertEqual(1, handler.publish_event.call_count) + event = handler.publish_event.call_args[0][0] + self.assertEqual(expected_string_representation, event.as_string()) + + +class TestReportFinishEvent(TestCase): + + def _report_finish_event(self, successful=None): + event_name, event_description = 'my_test_event', 'my description' + reporting.report_finish_event( + event_name, event_description, successful=successful) + return event_name, event_description + + def assertHandlersPassedObjectWithAsString( + self, handlers, expected_as_string): + for _, handler in handlers.items(): + self.assertEqual(1, handler.publish_event.call_count) + event = handler.publish_event.call_args[0][0] + self.assertEqual(expected_as_string, event.as_string()) + + @mock.patch('cloudinit.reporting.instantiated_handler_registry', + new_callable=_fake_registry) + def test_report_finish_event_passes_something_with_as_string_to_handlers( + self, instantiated_handler_registry): + event_name, event_description = self._report_finish_event() + expected_string_representation = ': '.join( + ['finish', event_name, event_description]) + self.assertHandlersPassedObjectWithAsString( + instantiated_handler_registry.registered_items, + expected_string_representation) + + @mock.patch('cloudinit.reporting.instantiated_handler_registry', + new_callable=_fake_registry) + def test_reporting_successful_finish_has_sensible_string_repr( + self, instantiated_handler_registry): + event_name, event_description = self._report_finish_event( + successful=True) + expected_string_representation = ': '.join( + ['finish', event_name, 'success', event_description]) + self.assertHandlersPassedObjectWithAsString( + instantiated_handler_registry.registered_items, + expected_string_representation) + + @mock.patch('cloudinit.reporting.instantiated_handler_registry', + new_callable=_fake_registry) + def test_reporting_unsuccessful_finish_has_sensible_string_repr( + self, instantiated_handler_registry): + event_name, event_description = self._report_finish_event( + successful=False) + expected_string_representation = ': '.join( + ['finish', event_name, 'fail', event_description]) + self.assertHandlersPassedObjectWithAsString( + instantiated_handler_registry.registered_items, + expected_string_representation) + + +class TestReportingEvent(TestCase): + + def test_as_string(self): + event_type, name, description = 'test_type', 'test_name', 'test_desc' + event = reporting.ReportingEvent(event_type, name, description) + expected_string_representation = ': '.join( + [event_type, name, description]) + self.assertEqual(expected_string_representation, event.as_string()) + + +class TestReportingHandler(TestCase): + + def test_no_default_publish_event_implementation(self): + self.assertRaises(NotImplementedError, + reporting.ReportingHandler().publish_event, None) + + +class TestLogHandler(TestCase): + + @mock.patch.object(reporting.logging, 'getLogger') + def test_appropriate_logger_used(self, getLogger): + event_type, event_name = 'test_type', 'test_name' + event = reporting.ReportingEvent(event_type, event_name, 'description') + reporting.LogHandler().publish_event(event) + self.assertEqual( + [mock.call( + 'cloudinit.reporting.{0}.{1}'.format(event_type, event_name))], + getLogger.call_args_list) + + @mock.patch.object(reporting.logging, 'getLogger') + def test_single_log_message_at_info_published(self, getLogger): + event = reporting.ReportingEvent('type', 'name', 'description') + reporting.LogHandler().publish_event(event) + self.assertEqual(1, getLogger.return_value.info.call_count) + + @mock.patch.object(reporting.logging, 'getLogger') + def test_log_message_uses_event_as_string(self, getLogger): + event = reporting.ReportingEvent('type', 'name', 'description') + reporting.LogHandler().publish_event(event) + self.assertIn(event.as_string(), + getLogger.return_value.info.call_args[0][0]) + + +class TestDefaultRegisteredHandler(TestCase): + + def test_log_handler_registered_by_default(self): + registered_items = ( + reporting.instantiated_handler_registry.registered_items) + for _, item in registered_items.items(): + if isinstance(item, reporting.LogHandler): + break + else: + self.fail('No reporting LogHandler registered by default.') + + +class TestReportingConfiguration(TestCase): + + @mock.patch.object(reporting, 'instantiated_handler_registry') + def test_empty_configuration_doesnt_add_handlers( + self, instantiated_handler_registry): + reporting.add_configuration({}) + self.assertEqual( + 0, instantiated_handler_registry.register_item.call_count) + + @mock.patch.object( + reporting, 'instantiated_handler_registry', reporting.DictRegistry()) + @mock.patch.object(reporting, 'available_handlers') + def test_looks_up_handler_by_type_and_adds_it(self, available_handlers): + handler_type_name = 'test_handler' + handler_cls = mock.Mock() + available_handlers.registered_items = {handler_type_name: handler_cls} + handler_name = 'my_test_handler' + reporting.add_configuration( + {handler_name: {'type': handler_type_name}}) + self.assertEqual( + {handler_name: handler_cls.return_value}, + reporting.instantiated_handler_registry.registered_items) + + @mock.patch.object( + reporting, 'instantiated_handler_registry', reporting.DictRegistry()) + @mock.patch.object(reporting, 'available_handlers') + def test_uses_non_type_parts_of_config_dict_as_kwargs( + self, available_handlers): + handler_type_name = 'test_handler' + handler_cls = mock.Mock() + available_handlers.registered_items = {handler_type_name: handler_cls} + extra_kwargs = {'foo': 'bar', 'bar': 'baz'} + handler_config = extra_kwargs.copy() + handler_config.update({'type': handler_type_name}) + handler_name = 'my_test_handler' + reporting.add_configuration({handler_name: handler_config}) + self.assertEqual( + handler_cls.return_value, + reporting.instantiated_handler_registry.registered_items[ + handler_name]) + self.assertEqual([mock.call(**extra_kwargs)], + handler_cls.call_args_list) + + @mock.patch.object( + reporting, 'instantiated_handler_registry', reporting.DictRegistry()) + @mock.patch.object(reporting, 'available_handlers') + def test_handler_config_not_modified(self, available_handlers): + handler_type_name = 'test_handler' + handler_cls = mock.Mock() + available_handlers.registered_items = {handler_type_name: handler_cls} + handler_config = {'type': handler_type_name, 'foo': 'bar'} + expected_handler_config = handler_config.copy() + reporting.add_configuration({'my_test_handler': handler_config}) + self.assertEqual(expected_handler_config, handler_config) |